Metal bending machine



March 6, 1962 J. M. WHITE ET Ai.

METAL BENDING MACHINE 3 Sheets-Sheet 1 Filed Jan. '7, 1959 March 6, 1962J. M. WHITE EI'AL 3,

METAL BENDING MACHINE Filed Jan. 7, 1959 s Sheets$heet 2 EEE '7.

March 6, 1962 J. M. WHITE ETAL 3,023,300

METAL BENDING MACHINE Filed Jan. '7, 1959 3 Sheets-Sheet 3 I28 I32 I34!71 Mm INVENTORS ATTORNEY United States Patent 9 3,023,800 METAL BENDINGMACHINE James M. White, Jack W. Cardwell, Robert F. Davissou, and RalphP. Brooks, Knoxville, Tenn., assignors to Greenway Industries,Knoxville, Team, a partnership Filed Jan. 7, 1959, Ser. No. 785,393 8Claims. (Cl. 153-56) This invention relates generally to sheet metalbending or forming machines and more particularly provides an improvedmachine capable of forming into not only flat curved shapes strip andsheet metal but also metal having an angular cross section whileautomatically varying the curvature during the forming operation.

The prior art provides machines for bending strip or sheet metal whichemploy feed rolls to pass the work toward an adjustable roll that formsthe metal to a predetermined radius of curvature. Such machines,however, are incapable of varying the curvature of the metal during theforming pass so as to produce sheet bent into a noncircular onnoncylindrical form. Nor are such machines capable of forming stripmetal having an angular cross section since the angle flange cannot beaccommodated between the feed rolls without deformation of either therolls or the metal flange.

Accordingly, it is a primary object of this invention to provide animproved machine capable of automatically forming both angle section andfiat sheet metal into either circular or noncircular shape.

Another object of the invention is to provide a metal rolling machineemploying a pair of driven feed rolls with a forming roll, whose axis ispivoted about one of the feed rolls, together with means forautomatically moving the forming roll so as to vary the curvature of thework metal during the forming pass.

A further object of the invention is to provide a metal rolling machineof the character indicated in which the variation of curvature in thework metal is obtained by means of an oscillating or revolving cam,operated from the single source of power for the feed rolls through anadjustable speed reducer and linkage including a rocker shaft, which iseffective to move the forming roll about one of the feed rolls duringthe work pass.

Yet another object of the invention is to provide a metal rollingmachine of the character indicated in which, in addition to the speedreducer for controlling the cam movement and hence the rate of change ofcurvature in the formed work, the linkage between such reducer and camis also adjustable so as to vary the cam movement in accordance with thelength of metal to be formed.

Still another object of the invention is to provide a metal rollingmachine employing a pair of driven feed rolls and a forming roll inwhich at least one of the rolls is circumferentially grooved toaccommodate the flange of an angle section work strip during its passbetween the feed rolls and to prevent twisting thereof during theforming operation.

A further object of the invention is to provide a metal rolling machinecapable of forming metal strip of relatively great length into complexshape of varying curvature, and whose feed and forming rolls areassembled in sections transverse to their axes or otherwise separated orslotted to accommodate work strips of angle section.

A still further object of the invention is to generally improve andsimplify metal rolling or bending machines.

The novel features that are considered characteristic of the inventionare set forth with particularity in the appended claims. The inventionitself, however, both as to its organization and its method ofoperation, together with additional objects and advantages thereof, willbest be understood from the following description of specificembodiments when read in connection with the accom- 7 screws 24 are icepanying-drawing, wherein like reference characters indicate like partsthroughout the several figures and in which:

FIGURE 1 is a view in front elevation of a machine constructed inaccordance with the invention;

FIG. 2 is a side elevation of the machine with a portion of a rollbearing side wall broken away to reveal interior details;

FIG. 3 is a cross section taken on the line 33 of FIG. 2;

FIG. 4 is an enlarged fragmentary section through the feed rolls of themachine showing a work strip of angle section being passed therethrough;

FIG. 5 is a plan view of an article of manufacture whose frame isadapted to be formed in the machine of FIGS. 1-4;

FIG. 6 is a sectional view taken on the line 66 of FIG. 5 and looking inthe direction of the arrows;

FIG. 7 is a diagram fragmentarily showing the relative positions of theforming and feed rolls and the cam control elements at a certain instantduring a work pass;

FIG. 8 is a diagram similar to FIG. 7 but showing the relationship ofthe elements at a different instant during a work pass;

FIG. 9 is a diagram similar to FIGS. 7 and 8 illustrating the effect ofdifferent adjustments of the cam operating linkage;

FIG. 10 is a fragmentary elevation of a machine detail illustrating themethod of locking the cam so as to fix the forming roll and produceshapes of circular outline;

FIG. 11 is a fragmentary elevational view showing a modified cam whichmay be used in the machine of FIGS. 1-4; and

FIG. 12 is a side elevation of a modified roll which may be used in themachine.

Referring now to the drawings in detail, the main support frame, of themachine shown in FIGS. 1-3, comprises a skeleton table 19 and legs 12upon which are suitably mounted roll bearing side walls 14 and 16. Theparallel rolls 28 and 30 constitute feed rolls and define a pass throughwhich is fed the metal sheet or angle strip 11,.FIGS. 3 and 4. The roll32 is a bending or forming roll movable with respect to the feed rolls.Means are provided whereby the upper feed roll 28 may be adjusted withrespect to the lower feed roll to obtain the desired spacing andpressure in accordance with the gauge of the .metal being formed, andwhereby the third or bending roll 32 may be adjusted with respect to theroll pass to obtain the desired curvature of the formed metal. Thesemeans include slots or guideways 18 in the upper edges of Walls 14 and16 for mounting the bearing blocks 20 which support the bearings for theends of shaft 36 for the roll 28. The shaft 38 of the lower feed roll 30is journaled in a pair of fixed bearing blocks 22. Adjusting threadedthrough the bearing braces 26 and are connected at their inner ends tothe blocks 20. By adjusting these screws the desired feed roll settingmay be obtained. The forming roll 32, which is an idler roll, is mountedto rotate about spindles 49 carried by a pair of triangular members orplates 34 near one corner thereof. The plates 34 are in turn pivotallymounted near a second corner to move about one of the feed roll shafts,such as the lower shaft 38. The means for moving the bending roll 32include a cam follower 46, which may be in the form of a wheel, whosecircumference may be grooved if desired, journaled on a stub shaft 48projecting from the third corner of each plate 34. The mechanism forcontrolling the movement of cam follower 46 will be described laterherein. At least one of the described rolls is provided with one or moretransverse grooves or slots 29 which are adapted to accommodate flangeson the work material.

.The machine is preferably powered by a single electric motor, such asindicated at 60, mounted on table at one side of the rolls. The outputof motor 60 is transmitted to the feed rolls through a conventionalspeed reducer 62 having a small output gear 64 meshing with a large gear66 which is keyed to shaft 38 of the lower feed roll 30. A second,smaller gear 68 on shaft 38 transmits power to drive the upper feed roll28 through gear 70. Since the vertical adjustment of feed rolls 28 and30 is relatively small, the gears 68 and 70 will always remain in mesh.

The power for moving the forming roll 32 is also preferably taken fromthe single power source, which is the motor 60. The output shaft ofspeed reducer 62 is provided with a gear sprocket 72 (FIG. 2) which isflexibly linked by a chain 76 with a sprocket 74 keyed to the inputshaft of a second speed reducer 78. The speed reducer 78 is of aconventional type capable of adjustment to yield variable speeds at itsoutput shaft 82. For this purpose an adjustment knob 80 is provided atone side of the speed reducer accessible to the operator. An indicator79 is visible at the front of speed reducer 78 to show the adjustedspeed for which the device is set. The speed reducer 78 is supported inany suitable way under the skeleton table 10, as by means of a platform81 hung by struts.

A rocker or cam shaft 94 is journaled in bearings 95, '97 and 99 abovethe table 10 so as to oscillate on its axis which parallels feed rollshafts 36 and 38. Movement is imparted to cam shaft 94 by means of alink 88 which passes through an opening in table 10 and is pivotallyconnected at its ends to the crank arms 90 and 84 respectively fixed tothe cam shaft 94 and output shaft 82 of the speed reducer by means ofcollars 92 and 85. The crank arm 84 is longitudinally slotted at 86 toprovide adjustment of its effective length by the nut 87 threaded on thecrank pin which forms the lower pivot of link 88.

A pair of collars 96, FIG. 1, are fixed in'spaced relation to each otheron cam shaft 94 under the forming roll 32. A cam 98, which may be in thesimple form of a thin plate having an arcuate edge 106, FIGS. 2 and 3,is bolted as at'101 to each collar 96. The arcuate edges 106 are adaptedto engage the cam followers 48 and "to elevate or lower plates 34 withturning movement about roll shaft 38 upon rotation of the cam shaft.94.Such pivotal movement of plates 34 carries the forming roll 32 acrossthe path of the work pass and toward or away from the upper feed roll28. To vary the radius of curvature being applied to the metal beingworked by the forming roll, the curved edges 1060f cams 98 arepreferably formed with a central portion having little curvature; thecurvature of the end portions being gradually increased toward the outerends of the cam.

One of the collars 96 is preferably provided with a locking projection100 having an aperture 102 .for reception of a locking member such asthe threaded clevis rod 126, FIG. 10. The rod may be inserted throughanopening in a bracket 104 fixed to the table 10. A bolt 127 is .passedthrough the clevis end of rod 126 and through opening 102 to hold thecam 98 in any desired position. The lock nuts 130 adjustably clamp therod 126 to the bracket 104. When the cams 98 are locked in agivenposition, by fastening the rod 126 to the locking projection 100, theforming roll 32 will idle around a stationary axis, so as to form thework into a circular or cylindrical shape with a fixed radius of curve.During such an operation, the link 88 is disconnected from crank arms 90and 84 to prevent rotation of the rocker shaft '94.

An additional idler roll 42 is provided at the rear of the machine andjournaled between the walls 14 and 16 so that its axis 44 is parallel tothe axes of the .feed rolls 28 and 30. The roll 42 supports and guidesthe work being fed into the pass between the rolls 28 and .30. To assistin alignment of the work metal edge, a vertical guide roller 50 isjournaledin a bracket-52 supported from the wall 16 at the rear of themachine. A similar,

but inclined roll 54 is journaled n th g sk a the front of wall 16 toguide the work metal as it reache the front of the machine. The blacket56 15 mounted on a support 59, which in turn is Secured to Wall 16 bysuitable means such as the bolts 58. The suPP 59 can be removed fromwall 16 and attached to the wall 14 so as to guide the work pass through1 a l a .along its other edge. Similarly, the guide roll may P mQved tothe other side of the machine, or addit lp l guide Toners may bepermanently afiixed there.

The operation of the machine will be qeswbed m relation to the formingof a typical specific objf p l as the frame 11 illustrated in FIGS. 5and 6 on egre l reduced scale. The frame 11 encloses an illuminad flelliptically-shaped sign such as those in common use in outdoorinstallations, notably at filling stations to advertise gasolineproducts. These signs are generally of considerable size varying inaxial length from about 6 feet to as much as 22 feet. Sometimes thesigns are circular rather than elliptical. The elliptical signs arecomprised of a pair of elliptical translucent plates 120 formed of aplastic, such as methyl methacrylate, and bearing indicia, not shown.Each plate 120 is held between the flnges 13 of the frame 11. The frameis F-shaped in cross section so as to provide two spaced parallelflanges 13 at right angles to the web of the frame. To permit assemblyof the plates 120, each frame 11 is formed in half sections, i.e.,semi-ellipses between which a plate 120 is placed. The frame sectionsare butted and welded to each other or more generally to the closuremember 122, which is thin sheet metal wrapped around both frames toconform to the shape thereof. The interior of the sign thus assembledhouses illuminating means,- not shown.

The forming of a semielliptical portion of frame 11 may, for example,require the shaping of an 18-footlengtl1' of metal, of extruded F-shapecross section, into an ap= proximately 11-foot length half ellipse. Themachine provided by the present invention is prepared for this operationby setting the cam 98 at its center; i.e., at about the position shownin FIG. 2. The speed reducer 78 is adjusted by means of knob to rotateits output shaft 82 one turn for the number of turns of the feed rolls28 and 30 required to move the work 18 feet, i.e., the peripheral lengthof the semiellipse to be formed. The power is then turned on to operatemotor60 causing the 18-foot angle extrusion 11 to be fed between therollers 28 and 30 from the rear with one edge of the extrusion guided byroller 50 and the web supported and guided by roller 42. The flanges 13of the work metal are received in the grooves 29 of the upper feed roll28 as best shown in FIG. 4. When the motor 60 starts, the cam 98,-controlled by the link 88 and crank arm 84, begins to turn in thedirection of the arrow shown in FIG. 3. As a result of the movement ofthe cam follower 48 on the arcuate edge 106 of the earn, the formingroll 32 will be elevated at first slowly and then more rapidly as theend of the cam is approached. This will cause the forming roll to bendthe frame member 11, at first, to a largeradius of curvature, andprogressively, to a smaller and smaller radius of curvature. Thisforming action is illustrated diagrammatically in FIGS. 7 and 8. FIG. 7shows the position of the cam '98 and its direction of movement as thecam follower 46 approaches one end of the cam. The work metal '11 hasalready been formed with little curvature, practically a straight line,at the beginning of the pass and an ever increasing curvature as thecamfollower ap proaches the cam end. As the crank arm 84 continues to turnclockwise, the crank arm on cam shaft '94 will come to a stop and thenreverse direction. As shown in FIG. 8, the cam follower 46 will thenmove back from the outer end of the cam 98 toward the center. Duringthis reverse movementof the follower, the roll '32 will be lowered, atfirst rapidly and then progressively more slowly. This will completethebending er the-frame 11 into a half ellipse with the cam follower comingto rest at the center of cam 98. This operation may be repeated fourtimes to form the sections needed to frame the sign of FIGS. 5 and 6.Four individual lengths of 18- foot angle section, metal strip are thuspassed through the machine separately and as each length feeds, the cam98 oscillates through an arc of approximately 90, in one direction andthen in the reverse direction, to raise and lower forming r011 32 atvarying rates and produce the semielliptical shape required.

If it is desired to form an ellipse of different length and curvature,the speed reducer 78 may be adjusted so that its output shaft revolvesonce during the pass of the new length of material to be formed. Anadditional adjustment may be made in the crank arm 84, which may beeffectively shortened or lengthened by loosening the nut 87, sliding thecrank pin in slot 86 to another point, and retightening the nut 87. Asdiagrammed in broken lines in FIG. 9, the crank pin or pivot of link 88will then have a smaller locus, circle 114 rather than the circle 110.As the crank arm 84 makes one revolution, the crank pin connecting link88 to crank arm 90 will then describe a shorter are, 116 rather than112. Thus, the arc of rotation of the cam shaft 94, and hence of the cam98, is shortened when the crank arm is adjusted to a shorter length.Consequently, the movement of the forming roll 32 will be changed toreduce the difference in the radius of curvature being formed in thework.

If it is desired to form the work with a constant radius of curvature,the cam 98 is set at a position which will yield the desired curvatureand is fastened in such position by the means shown in FIG. 10. Aspreviously explained, the locking rod 126 is inserted through theopening in the lug 104 and adjusted so that its clevis end may be boltedto the projection 100 carried by the collar 96. When the cam is sofastened, it is necessary to disconnect the link 88 so that rotationwill not be imparted from the speed reducer output shaft 82 to the camshaft 94.

If it is desired to form the half of the ellipse alternate to that shownin FIG. 8; i.e., a semiellipse with a short radius of curvature portionat each end and a large radius of curvature in the center, the cam 108shown in FIG. 11 may be substituted for cam 98. The cam 108 has anarcuate surface 106 similar to that of cam 98 but at one end the surface106 is abruptly merged into the surface portion 110. The cam follower 46is seated at the end of cam 108 on surface 110, and the speed reducerand crank shaft 84 are so adjusted that the cam shaft 94 will turnapproximately or just slightly more than 180 for one pass of the workmaterial. Upon starting the machine, the cam follower 46 moves quicklyfrom the surface 110 to surface 106 at the beginning of the work pass.Thus, the forming roll 32 will be quickly elevated to form the Workmaterial into the desired shape having a short radius of curvature atthe beginning and with gradually increased curvature until the camfollower reaches the center of cam 108. As the cam continues to rotatein the same direction, the curvature is first gradually and then rapidlydecreased until the cam follower stops on the end of cam 108. Inutilizing the substitute cam 108, the speed reducer output shaft turns180 during the work pass, and during the subsequent half turn the camreverses direction and returns to its starting position. After forming,it may be necessary or desirable to cut off the short piece ofnonelliptic shape formed while the cam follower is on surface 110 ofearn 108.

In FIG. 12 is shown a modified roll which may be substituted for one ofthe feed rolls 28, 30 and if desired for the forming roll 32. Themodified roll is comprised of cylindrical sections indicated at 128,130, 132, 134, 136, and 138, all of different widths. The sections maybe slipped onto the shaft 36, having a longitudinal key 37, to assemblea roll of any width and to provide grooves between the sections atdesired locations for accommodating the flanges of the metal to beformed. The roller can thus be used to work metal of any width and anglecross section since the feed roll sections can be spaced to accommodatedifferent spacings and thicknesses of the angle. metal flanges. It isalso evident that the provision of the spaces between the roll sections,as previously described in connection with the grooves 29 of the roll28, serve to restrain the Work from twisting as it passes through themachine.

It will be apparent from the above description that the improved machinepermits the forming of sheet and strip metal including metal havingangular cross sections. The machine is capable of forming long lengthsof metal angle strip into complex, noncircular, curved shapes as well ascircular shapes. The radius of curvature may be automatically variedduring the work pass by preadjustment of the speed reducer and length ofits crank arm. In addition, cams of different shapes, or cranks andlinks of different lengths, may be substituted to form the metal into alimitless variety of curves.

Although certain specific embodiments of the invention have been shownand described, it is obvious that many modifications thereof arepossible. The invention, therefore, is not to be restricted exceptinsofar as is necessitated by the prior art and by the spirit of theappended claims.

We claim:

1. In a machine for bending angle section strip material into curvedform, the combination of a pair of elongated cylindrical, axiallyparallel, feed rolls adapted to pass a strip between them, a formingroll whose axis is parallel to the axes of the feed rolls and which ispivotally supported with respect thereto so as to swing about a lineparallel to the axis of one feed roll, one only of said feed rolls beingformed of separate cylindrical sections of different widths mounted on alongitudinally keyed shaft and adjustable longitudinally of the shaft toprovide groove-like spaces in the roll at any desired locationsconforming in shape to a flange of said strip and embracing both sidesof the flange to prevent twisting of the strip during the forming pass,power means for driving said feed rolls, and means for automaticallymoving said forming roll during the work pass to vary the radius ofcurvature of the strip being passed by the feed rolls.

2. In a machine for bending angle section strip material into curvedform, the combination of a pair of driven feed rolls adapted to pass astrip between them, a forming roll mounted between members pivoted toone of said feed rolls and movable with respect to the feed rolls toengage the strip and vary the radius of curvature of the strip beingpassed by the feed rolls, one of said feed rolls being provided with acircumferential groove conforming in shape to a flange of said strip andembracing the flange to prevent twisting of the strip during the formingpass, means for driving said feed rolls, and means for automaticallymoving said forming roll with respect to the feed rolls during pass ofthe strip, said last named means including a rocker shaft having a cam,means for oscillating said cam in proportion to the feed of the workbeing formed, a follower carried on one of said pivoted members tofollow said cam and vary the position of the forming roll, a variablespeed reducer connected to said means for driving the feed rolls, acrank on the output of said speed reducer, a crank on said rocker shaft,and a link pivotally connected to said cranks.

3. A machine for bending sheet material according to claim 2 wherein oneof said cranks is provided with means for adjusting its length wherebyto vary the length of the arc of rotation of said rocker shaft and cam.

4. A machine for bending sheet material according to claim 3 whereinsaid means for adjusting the crank length comprises a longitudinal slotin the arm of said crank on said variable speed reducer, a crank pin onsaid link slidable in said slot, and a nut on said pin to fasten thelink to the crank arm at any desired point to effectively vary thelength of the crank arm.

' 75 machine for bending sheet material according to 7 claim 2 whereinadditional means is provided for locking said rocker shaft to permitforming the work stripinto a shape having a constant radius ofcurvature.

'6. In a machine for bending strip material into curved form, thecombination of a pair of driven feed rolls adapted to pass a stripbetween them, a forming roll movable with respect to the feed rolls toengage the strip and vary the radius of curvature of the strip beingpassed by the feed rolls, means for driving said feed rolls at a givenspeed, and means for automatically moving said forming roll with respectto the feed rolls during pass of the strip, said last named meansincluding a rocker shaft having a cam, means for oscillating said cam ata speed in proportion to said given speed of 'the feed rolls, a.follower secured to said forming roll to follow said cam and vary thepositionof the forming roll, and'adjustable means for varying the speedof rotation of said cam with respect to said given speed of the feedrolls whereby lengths'of strip material may be formed into shapes ofdilferent curvature.

7. In a metal working machine, a pair of rolls adapted to pass a stripbetween them, means for advancing a strip of stock to pass between saidrolls at a given speed, a forming roll operable to engage the stripbeyond the pass to bend the strip into curved form, means including arotatable cam for automatically moving the forming roll with respect tosaid pair of rolls to vary the radius of curvature imparted to the stripduring its pass, and adjustable means for varying the speed of rotationof said cam with respect to the said given speed of advance of the stripthrough the feed pass whereby various lengths of stock may be formedinto shapes of different curvature.

8. In a metal working machine, the combination set forth in claim 7wherein said means for varying the speed of rotation of said camcomprises a source of power for driving said pair of rolls and avariable speed reducer whose input shaft is also connected to saidsource of power and whose output shaft is connected to drive said cam.

References Cited in the file of this patent UNITED STATES PATENTS

